The cell-forward access channel (CELL-Forward Access Channel, CELL_FACH) state is a state of a user equipment (User Equipment, UE) in a universal mobile telecommunications system (Universal Mobile Telecommunications System, UMTS).
To save energy consumption of a UE, a UE in CELL-FACH state has a discontinuous reception (Discontinuous Reception, DRX) mechanism. The minimum length of a time period during which data can be received (Discontinuous Reception-on, DRX on) within a DRX cycle (cycle) is 10 ms (that is, the length of one radio frame), and the maximum DRX cycle length is 320 ms (that is, the length of 32 radio frames). The DRX cycle length and the DRX on length are configured for a UE by a radio network controller (Radio Network Controller, RNC) through a system message, and are configured for a base station (for example, a NodeB) through common signaling at the same time. DRX-on timing is calculated by a UE and a NodeB through a high speed downlink shared channel-radio network temporary identifier (High Speed Downlink Shared Channel-Radio Network Temporary Identifier, H-RNTI) of the UE, the DRX cycle length, and the DRX_on length, respectively, which is as follows: (SFN-H-RNTI+65536) mod DRX_cycle<DRX_on. The value of a system frame number (System Frame Number, SFN) is 0˜4095, one SFN denotes 10 ms, the value of the DRX_cycle length can be 4, 8, 16 or 32 radio frames, the value of the DRX_on length can be 1, 2, 4, 8 or 16 radio frames, and the length of one radio frame is 10 ms. For a NodeB, when a T321 timer expires, data can be sent to the UE only in the case that the SFN meets the foregoing inequality. Correspondingly, for the UE, when the T321 timer expires, downlink data can be received only in the case that the SFN meets the foregoing inequality.
To further save the energy consumption of the UE, s shorter DRX-On length can further be set. For example, the DRX-On length may be set to 2 ms. In this case, one DRX cycle with the length of 10 ms includes 5 radio subframes. During the implementation of the present invention, the inventor finds that the prior art has at least the following disadvantages: when the foregoing solutions in the prior art are adopted, it cannot be accurately determined on which radio subframe DRX-on specifically is, resulting in low data processing efficiency.